1. Field of the Invention
The present invention is for use in an evaporative air cooling system for residential or commercial use and specifically permits dampening the system during periods of non-use; to restrict energy loss; to reduce dust intake; and to reduce internal corrosion of the system.
2. Prior Art
Evaporative air conditioning systems are used in residential and commercial applications for cooling the inside of a structure. The system has an external unit that permits air to be drawn into it through vented sides. Moisture is added to the air it is forced through an air-duct to a diffuser located in the ceiling of the structure. The diffuser selectively directs the cooled air throughout the structure. The diffuser and vents are normally formed from sheet metal. The diffuser is normally secured to the end of the air duct by sheet metal screws.
This type of a cooling system is a very economical method of cooling certain structures. However, it creates numerous problems during times of non-use. The biggest problem is that the venting system creates a natural escape path for warm air, during periods when the structure is being heated. Consequently, rising hot air escapes the structure and significantly increases the energy use during heating periods. During these heating periods when the inside of the structure has a positive air pressure the rising hot air is pushed out through the air-ducts to the outside and when a negative air pressure is present inside the structure, cold outside air is sucked into the structure through the air-ducts.
In order to prevent this heat loss, diffusers were constructed with vents that could to selectively open and close. However, the vents can not be constructed so as to be air tight and additionally, the sheet metal skin has no insulative capabilities. Cloth covers were also devised to fit over the outside unit to restrict the heat loss. Those outside covers inherently have the same problems as the opening/closing diffuser, i.e. no insulative capabilities and they can not be sealed so as to be air tight. Neither method alone or in combination are effective to prevent heat loss from a structure during heating periods.
The heat loss problem is exacerbated because of the size of the air ducts. The duct work is typically 17 inches or greater. This size of duct creates a significant path for energy loss.
Additionally, the rising hot air is saturated with moisture. As it rises in the air vents, it condenses. The moisture then causes the vents to rust and corrode. This phenomena only occurs during periods when the structure is being heated, and the heated moist air rises into the vents.
These air cooling systems are also known for their inability to prevent dust from entering the structure. This is especially true during periods of non-use of the air cooling system and when cooler pads are dry.
In order to help eliminate these problems users typically remove the diffuser and stuff insulating material into the vent near the diffuser. The procedure of removal of the diffuser is time consuming and difficult. Often the metal screws holding the diffuser, strip the holes and cause additional problems for reinstallation of the diffuser. The diffuser is also heavy and cumbersome and located in the ceiling of the structure. Its removal and reinstallation is not an easy project. However, the insulative material does help reduce the heat loss, but it is not air tight and the problems of energy loss, dust and corrosion continue to exist.
The only prior art device that is known to applicant is no longer marketed because; it was cost prohibitive, reduced the operating efficiency during cooling; difficult to install; and expensive to stock, display and ship because of its size. This device was attached to the air-duct at ceiling level. The diffuser was hinged at the ceiling to pivot downward. An insulative block was capable of being placed into clips on predisposed inner tabs that protrude into the air-duct to insulate the air duct.
This device was extremely costly to manufacture because of the specially designed and fabricated machine parts, i.e. hinges, latches and tabs. These parts had to be engineered to carry the entire weight of the diffuser, which is significant. The interior tabs on which the insulative member was placed protrude into the air-duct and restrict the airflow through the air-duct and restrict the airflow through the air duct. Typically these tabs reduced the opening size by 1 to 11/2 inches in each direction. A reduction, during cooling use, of the air duct by any amount significantly reduces the efficiency of the system.
This device is also difficult to install because of its weight and size. The diffuser was hinged to a frame that could be attached to the ceiling and/or air-duct. The frame and diffuser are of sufficient weight and size that installation is difficult. Also the device could not simply be attached to the duct work with sheet metal screws because of its weight. The frame to which the diffuser is attached has to be capable of carrying the entire weight of the diffuser on the hinged side. This presents a significant problem in installations where no ceiling framing member is located near the air-ducts. This requires the mounting frame be made of heavier metal to accomodatethe additional weight.
The prior art device is also expensive to market because of its size and weight. The diffuser and frame are large and heavy. Shipping of large heavy packages is costly. Likewise, a retailer stocking such a product must have additional space to store and display the device.
The present invention provides a device that permits a diffuser to be quickly and easily removed and replaced or modified by an insulated member that completely seals and insulates the system during periods of non-use. The device permits conversion as frequently as needed, even on a daily basis. It completely eliminates the corrosion cycle by preventing hot air and moisture from entering the sir duct. Its seal is so effective it eliminates the dust problem and its insulative features are as good or better than most ceilings, so that energy loss is eliminated.